Representation of the gradual unzipping of one wall of a carbon nanotube to form a nanoribbon.National Nanomanufacturing Network: Take a carbon nanotube, split it down the middle and flatten it: what do you get? A graphene nanoribbon. While graphene itself is a material known for its strength and conductivity--as flat sheets of linked carbon--narrow ribbons of graphene can channel electrons length-wise, turning the the graphene into a semiconductor.
This week in Nature, James Tour and Dmitry Kosynkin from Rice University report a novel way to transform carbon nanotubes into nanoribbons. Their method, a room-temperature, chemical process, relies on sulfuric acid and potassium permanganate to effectively "unzip" the tubes. The process has been applied to single- and multi-walled carbon nanotubes, and allows for bulk production of ribbons.
This process could potentially make "billions of ribbons at once," Tour stated in a Nature podcast (April 16). With potential applications in conductive films for displays or solar panels, the process is attracting manufacturers looking for a simple, efficient, and scalable method to handle graphene. "As soon as we started talking about this process, we began getting calls from manufacturers that recognized the potential," reports Tour on Nanotechwire.
A complementary process, also reported in Nature this week by Liying Jiao and colleagues from Stanford University, uses a plasma etching process to render carbon nanotubes into semiconducting ribbons.